1. Pasolini P (1975) Corriere della Sera. Accessed 1 Feb 1975.
http://www.corriere.it/speciali/pasolini/potere.html
2. Kovarik B (1994) Charles F. Kettering and the 1921 discovery of tetraethyl lead. Society of automotive engineers, fuels and lubricants division conference, Baltimore, 1994.
http://www.environmentalhistory.org/billkovarik/about-bk/research/cabi/ket-tel/#earlyw
3. “Midge” to “My dear Boss” Kettering, 2 Mar 1923, Factory correspondence, unprocessed Midgley files, GMI. Quoted in [2]
4. New York Times, 25 Oct, section 9, p 14. Quoted in [2]
5. Frittoli E (2014) Eternit: la storia del cemento che uccide (1901–2014).
http://www.panorama.it/news/cronaca/eternit-storia-cemento-uccide-1901-2014/